Sure. 😉 Honestly this are pretty simple things, arent they? These one can - if he or she is wiiling to - learn pretty fast.
Of course. But as BC already pointed out: at least for me, the focal length and the aperture (or the corresponding DOF) are my main settings I adjust on the camera to create the effect I want. Sometimes shutter speed, too, if it's about freezing motion (or the contrary, when panning for example).
In case of equivalency, it is about few simple equations, for god’s sake. Of course it is correct as a concept. And of course it is useful if comparing different systems. But all of us have made a choice of a system, for whatever different reasons. And when going out with the system of your choice, what you have in your hand is what takes pictures, together with your skills, and there equivalent photograph is less then meaningless.